Portion of a shoe sole



FIG. 1 is a front perspective view of a portion of a shoe sole showing my new design;

FIG. 2 is a rear perspective view thereof; and,

FIG. 3 is a bottom plan view thereof.

The uneven broken line showing of the remainder of the shoe is for illustrative purposes only and forms no part of the claimed design. The unshaded areas form no part of the claimed design. 

The ornamental design for a portion of a shoe sole, as shown and described. 